Practitioners face many challenges when working with students who are experiencing difficulty with comprehension. The act of creating meaning with texts is complex, and comprehension is often measured in schools as a product of reading. Product assessments, such as answering questions or retelling a text, take place after reading, which makes it difficult to understand why and when a student may be experiencing difficulties. Using design-based research, the author examined the implementation of verbal protocols in classrooms as a formative assessment tool for comprehension. During this two-month study, three reading specialists drew on the landscape model of reading as a theoretical framework to better understand their students' think-aloud statements. Findings indicated that reading specialists implemented verbal protocols as a formative assessment tool with diagnostic interpretation about their students' reading difficulties and were able to use this information to effectively coach students on their reading processes.